Intraocular, Accommodating Lens And Methods Of Use

ABSTRACT

An intraocular lens is adapted for insertion into a capsular bag having a zonular contact region. The intraocular lens comprises a shape changing optical element and an accommodating element comprising at least one force transmitting element and a plurality of spaced apart contacting elements each adapted to contact a portion of the zonular contact region and transmit compressive displacement radially inward at an oblique angle to the optical element and configured to cooperate with at least one of the ciliary muscle of the mammalian eye, the zonules of the mammalian eye and the vitreous pressure in the eye to effect an accommodating shape and a disaccommodating shape change to the optical element.

REFERENCE TO PRIORITY DOCUMENT

This application is a continuation of co-pending U.S. patent applicationSer. No. 12/341,799, entitled, “INTRAOCULAR, ACCOMMODATING LENS ANDMETHODS OF USE,” filed Dec. 22, 2008, which claims priority to U.S.Provisional Patent Application Ser. No. 61/017,150 entitled“INTRAOCULAR, ACCOMMODATING LENS AND METHODS OF USE,” filed Dec. 27,2007. Priority of the aforementioned filing dates is hereby claimed andthe disclosures of the applications are hereby incorporated by referencein their entirety.

BACKGROUND

The present disclosure relates generally to the field of ophthalmics,more particularly to ophthalmic devices, including intraocular lenses(IOLs) such as accommodating intraocular lenses.

A healthy young human eye can focus an object in far or near distance,as required. The capability of the eye to change back and forth fromnear vision to far vision is called accommodation. With reference toFIG. 1A, accommodation occurs when the ciliary muscle CM contracts tothereby release the resting zonular tension on the equatorial region ofthe capsular bag. The release of zonular tension allows the inherentelasticity of the lens capsule to alter to a more globular or sphericalshape, with increased surface curvatures of both the anterior andposterior lenticular surfaces.

In addition, the human lens can be afflicted with one or more disordersthat degrade its functioning in the vision system. A common lensdisorder is a cataract which consists of the opacification of thenormally clear, natural crystalline lens matrix. The opacification canresult from the aging process but can also be caused by heredity ordiabetes. FIG. 1A shows a lens capsule comprising a capsular sac with anopacified crystalline lens nucleus. In a cataract procedure, thepatient's opaque crystalline lens is replaced with a clear lens implantor IOL.

In conventional extracapsular cataract surgery as depicted in FIGS. 1Band 1C, the crystalline lens matrix is removed leaving intact the thinwalls of the anterior and posterior capsules—together with zonularligament connections to the ciliary body and ciliary muscles. Thecrystalline lens core is removed by phacoemulsification through acurvilinear capsularhexis as illustrated in FIG. 1B, i.e., the removalof an anterior portion of the capsular sac. FIG. 1B depicts aconventional 3-piece IOL just after implantation in the capsular sac.

FIG. 1C next illustrates the capsular sac and a conventional 3-piece IOLafter a healing period of a few days to weeks. The capsular saceffectively shrink-wraps around the IOL due to the capsularhexis, thecollapse of the walls of the sac and subsequent fibrosis. With referenceto FIGS. 1B and 1C, cataract surgery as practiced today causes theirretrievable loss of most of the eye's natural structures that provideaccommodation. The crystalline lens matrix is completely lost-and theintegrity of the capsular sac is reduced by the capsularhexis. The“shrink-wrap” of the capsular sac around the IOL can damage the zonulecomplex, and thereafter it the ciliary muscles may atrophy. Thus,conventional IOL's, even those that profess to be accommodative, may beunable to provide sufficient axial lens spatial displacement along theoptical axis or lens shape change to provide an adequate amount ofaccommodation for near vision.

Accommodative Lens Devices

Several attempts have been made to make intraocular lenses that providethe ability to accommodate. Such attempts generally fall into twocategories: those that rely on changing the shape of optical elements,and those that rely on changing the relative position of one or moreoptical elements. In the second category, changes in power are broughtabout by making the intraocular lens or a lens component move back andforth (anterior and posterior) along the optical axis. Suchdisplacements change the overall optical power of the eye and may allowa patient to adjust his or her focus so as to create sharp retinalimages of objects over a range of distances. Examples of such attemptsare set forth in Levy U.S. Pat. No. 4,409,691 and several patents toCumming, including U.S. Pat. Nos. 5,674,282; 5,496,366; 6,197,059;6,322,589; 6,342,073; and 6,387,126.

Specially shaped haptics, levers or other mechanical elements have beendescribed to translate the radial compressive force exerted by thezonules to the desired axial displacement of a lens body, including inU.S. Pat. Nos. 7,018,409; 6,790,232; 6,524,340; 6,406,494; and6,176,878. These haptics are often fused to the capsular wall by thefibrosis occurring during the post-operative healing phase. Additionalexamples may also provide flexible hinge regions of the haptic tofacilitate axial displacement, including U.S. Pat. Nos. 5,496,366;6,969,403; 6,387,126 and 7,025,783. Several examples include annularrings elements to facilitate contact with the capsule and translation ofthe compressive application of force by the zonules to effect axialdisplacement of the lens body, including in U.S. Pat. Nos. 6,972,033 and6,797,004; and U.S. Publication No. 2004/0127984. However, many of theseIOL's are configured to be generally planar, and parallel to the planeof the lens, thus minimizing the natural spheroid shape of the capsularbag and reducing the natural accommodative ability of the eye. Thedisclosure of each of the aforementioned patents is incorporated hereinby reference.

In most of the aforementioned embodiments, the lenses are biased to belocated in the posterior-most position in the eye under rest or restingconditions. When near focus is desired, the ciliary muscle contracts andthe lens moves forwardly (positive accommodation). In the absence ofciliary muscle contraction, the lens moves rearwardly to itsposterior-most resting position. One problem that exists with such IOLsis that they often cannot move sufficiently to obtain the desiredaccommodation.

Accommodative lens designs with single or multiple optic lens assemblyhave been disclosed in U.S. Pat. Nos. 6,423,094; 5,275,623; 6,231,603;4,994,082; 6,797,004; 6,551,354; and 6,818,017. In these designs, theoptic diopter of an individual lens does not change during theaccommodation-unaccommodation process. Rather, the optic diopter powerof the assembly is dependent on the distance between the optic lenses.These designs also incorporate a framework that flexes about a generallyequatorial plane, orthogonal to the optical axis, to affect movement ofthe lens bodies at one or both distal framework ends along the opticalaxis. However, multiple lens systems can be cumbersome and also requirean axial displacement unachievable with a collapsed capsular bag andresulting ineffective accommodative mechanisms. Furthermore, IOL's ofthis configuration flex about a plane parallel to the plane of the lensbody, translating the compressive action of the accommodative mechanismsinto axial displacement along the optical axis. Thus the accommodativeeffect is to axially displace the optics along the optical axis, notprovide compressive force radially inward orthogonal to the opticalaxis.

On the other hand, lens surface shape changing, exemplified in thedisclosures of U.S. Pat. Nos. 4,842,601; 4,888,012; 4,932,966;4,994,082; 5,489,302; 6,966,049; and U.S. Publication Nos. 2003/0109926;2003/00639894; 20050021139A1; and 2005/1890576 have required a sphericallens shape to interact with the rim of ciliary muscle in more than onemeridian or even from all 360 degree orientations. This requires perfectlens centration in regard to the ciliary rim and equal interaction fromall meridians; otherwise, the absence of central lens symmetry leads tounequal lens surface curvature in different meridians with resultingreduction in image quality.

SUMMARY

Disclosed is a an intraocular lens (IOL) for insertion into a capsularbag having a zonular contact region. In an aspect, the intraocular lenscomprises a shape changing optical element and an accommodating elementcomprising at least one force transmitting element and a plurality ofspaced apart contacting elements each adapted to contact a portion ofthe zonular contact region and transmit compressive displacementradially inward at an oblique angle to the optical element andconfigured to cooperate with at least one of the ciliary muscle of themammalian eye, the zonules of the mammalian eye and the vitreouspressure in the eye to effect an accommodating shape and adisaccommodating shape change to the optical element.

In another aspect, there is disclosed a method of enabling lensaccommodation, comprising providing an accommodating element configuredfor contacting at least a substantial portion of the zonular region, theaccommodating element positioned relative to an optical element andconfigured to cooperate with at least one of the ciliary muscle of themammalian eye, the zonules of the mammalian eye and the vitreouspressure in the eye to effect an accommodating shape and adisaccommodating shape change to the optical element; and coupling ashape changing lens body to the accommodating element, wherein radialinward forces at the anterior and posterior capsular bag are transmittedthrough a generally medially disposed force transmitting element tocause a shape change to a surface curvature of the lens body, andwherein radial outward forces cause the accommodating element to cause asecond shape change to said lens curvature.

In another aspect, there is disclosed a method of enabling lensaccommodation, comprising: providing an accommodating element configuredfor contacting at least a substantial portion of the zonular region, theaccommodating element positioned relative to an optical element andconfigured to cooperate with at least one of the ciliary muscle of themammalian eye, the zonules of the mammalian eye and the vitreouspressure in the eye to effect an accommodating shape and adisaccommodating shape change to the optical element; and coupling ashape changing lens body to the accommodating element, wherein radialinward forces at the anterior and posterior capsular bag are transmittedthrough a generally medially disposed force transmitting element tocause a shape change to a surface curvature of the lens body, andwherein radial outward forces cause the accommodating element to cause asecond shape change to said lens curvature.

These general and specific aspects may be implemented using the devices,methods, and systems or any combination of the devices, methods andsystems disclosed herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective cut-away view of an eye with an opacified lenscapsule.

FIG. 1B is a perspective cut-away view of the eye of FIG. 1A with acurvilinear capsularhexis and the crystalline lens matrix removed withthe implantation of a 3-piece IOL.

FIG. 1C is a perspective cut-away view of the eye of FIG. 1B showing thelens capsule after wound healing wherein the lens capsule shrink wrapsaround the IOL

FIG. 1D is a perspective cut-away view of the eye of FIG. 1B showing thelens capsule and an IOL in accordance with one embodiment of the presentinvention.

FIG. 2 is a cross-sectional view of an IOL in accordance with oneembodiment of the present invention taken along the axis x-x of FIG. 1D.

FIG. 3 is a fragmentary cross-sectional view of an IOL in accordancewith one embodiment of the present invention taken generally along theline XX of the eye of FIG. 1D.

FIG. 4 is a fragmentary cross-sectional view of an IOL in accordancewith another embodiment of the present invention taken generally alongthe line XX of the eye of FIG. 1D.

FIG. 5 is a cross-sectional view of an IOL in accordance with anotherembodiment of the present invention take along a similar axis to that ofXX of FIG. 1D.

FIG. 6 is a fragmentary cross-sectional view of the capsular sac and onelinking arms embodiment of the present invention in an accommodativeshape.

FIG. 7 is a fragmentary cross-sectional view of the capsular sac and onelinking arms embodiment of the present invention in a disaccommodativeshape.

FIG. 8 is a fragmentary cross-sectional view depicting the accommodatingforces provided by an embodiment of the present invention.

FIG. 9 is a fragmentary cross-sectional view depicting the accommodatingforces provided by an embodiment of the present invention.

FIG. 10 is a top view taken along the optical axis of the capsular sacdepicting an embodiment of the accommodating element of the presentinvention.

FIG. 11 is a cross-sectional view of a combination contacting andaccommodating element embodiment of the present invention in combinationwith an accommodative lens.

FIG. 12 is a cross-sectional view of a combination contacting andaccommodating element embodiment of the present invention in combinationwith an optical element.

FIG. 13 is a cross-sectional view of another combination contacting andaccommodating element embodiment of the present invention in combinationwith an optical element.

FIG. 14 is a generally perspective view of another combinationcontacting and accommodating element embodiment of the presentinvention.

FIG. 15 is a fragmentary cross-sectional view of another embodiment ofthe combination contacting and accommodating element embodiment of thepresent invention.

FIG. 16 is a cross-sectional view of another embodiment of the ofcombination contacting and accommodating element embodiment of thepresent invention in combination with an optical element.

FIG. 17 is a cross-sectional view of an embodiment of the opticalelement of the present invention.

FIG. 18 is a cross-sectional view of another embodiment of the opticalelement of the present invention.

FIG. 19 is a cross-sectional view of another embodiment of the opticalelement of the present invention.

FIG. 20 is a cross-sectional view of another embodiment of the opticalelement of the present invention.

FIG. 21 is a front view along the optical axis of the embodiment of FIG.21.

FIG. 22 is a cross-sectional view of another embodiment of the opticalelement of the present invention.

FIG. 23 is a front view along the optical axis of the embodiment of FIG.23.

FIG. 24 is a embodiment of the optical element of the present inventionin a disaccommodative state.

FIG. 25 is a embodiment of the optical element of the present inventionin an accommodative state.

DETAILED DESCRIPTION Definitions

The terms zonular region or zonular contact region refer to the portionof the capsular bag that is typically contacted by or attached to thezonules. One way to describe the zonular contact region is as theportion of the capsular bag which is contacted by the zonules and whichcorresponds to that defined by the equatorial apices of the capsular bagand an orthogonal projection upon the capsular bag radius from theportion of the capsular bag contacted by the zonules. The determinationof a capsular bag radius dimension in its accommodative orunaccommodative states can be made in various manners. For example, thedetermination of capsular bag radius dimension in its accommodative orunaccommodative states can be made using the Scheimpflug slit imagetechnique (Dubbelman, Vision Research, 2001; 41:1867-1877), and IR videophotography (Wilson, Trans. Am. Ophth. Soc. 1997; 95:261-266). Theaforementioned references are incorporated herein by reference.Generally the zonular contact region is about 1.5-2.0 mm radially inwardfrom the equatorial apices along the capsular bag radius.

The term percentage (X %) of zonular contact refers to the contact orattachment area along the capsular bag defined by the equatorial apicesof the capsular bag and an orthogonal from a given percentage (%) of thecapsular bag radius defining the zonular contact region. For example,contacting 50% of the zonular contact region refers to contacting thatportion of the capsular bag that corresponds to the portion defined bythe equatorial apices and a radii of 50% of the zonular contact regionradii. For the purposes of example, if the zonular contact region has aradii of 1.5 mm, then the respective 50% would be that region defined bythe equatorial apices and a contact region defined in part by theorthogonal at 0.75 mm or an orthogonal projection from 0.75 mm radiallyinward from the equatorial apices.

The term anterior portion of the zonular region refers to the mostanterior portion of capsular bag contacted by the zonular region.

The term posterior portion of the zonular region refers to the mostposterior portion of the capsular bag contacted by the zonular region.

The term shape changing optical element refers to an optical elementthat is made of material that enables the optical element to alter itsshape, e.g., become one of more spherical in shape, thicker or focus ona closer object; or become more ovoid in shape, thinner or focus on amore distant and thus alter the optical element's respective optics(alter the diopters of the resulting optical element).

The term accommodating shape refers to the shape of the optical elementwhen at least one of the tensioning of the ciliary muscle of themammalian eye, the zonules of the mammalian eye and a change in thevitreous pressure in the eye effect equatorial or polar distention ofthe capsular bag to effect a focusing upon a closer object. Anaccommodating shape is generally more spherical than thedisaccommodating shape.

The term disaccommodating shape refers to the shape of the opticalelement when at least one of the relaxation of the ciliary muscle of themammalian eye, the zonules of the mammalian eye and a change in thevitreous pressure in the eye and a comcomittant return to a morespherical shaping of the capsular bag to effect a focusing upon a moredistant object. A disaccommodating shape is generally more ovoid thanthe accommodating shape.

Capsulorhexis is the opening surgically made by puncturing, thengrasping and tearing a hole in the anterior capsule. In a regularextracapsular cataract extraction (ECCE) procedure, a capsulorhexis ismade in the anterior capsule and the cloudy cataract lens is extractedby phacoemulsification. The accommodative IOL described herein can beused for patients after cataract surgery. It can also be used forpatients with only presbyopia, but without cataract.

The term diopter (D) refers to the reciprocal of the focal length of alens in meters. For example, a 10 D lens brings parallel rays of lightto a focus at ( 1/10) meter. After a patient's natural crystalline lenshas been surgically removed, surgeons usually follow a formula, based ontheir own personal preference, to calculate a desirable diopter power(D) for the selection of an IOL for the patient to correct the patient'spreoperational refractive error. For example, a myopia patient with −10D undergoes cataract surgery and IOL implantation; the patient can seeat a distance well enough even without glasses. This is because thesurgeon has taken the patient's −10 D near-sightedness into account whenchoosing an IOL for the patient.

The term medially disposed within the capsular sac refers to beingdisposed within the generally equatorial region of the capsular bag,e.g., between the anterior and posterior portions of the capsular bag.One method of describing the region is that region corresponding to thezonular contact region, to 67%, 50%, 33%, 25%, 10% region encompassingregion along the optical axis centered between the most anterior portionof the capsular bag and the most posterior portion of the capsular bag.

Exemplary Embodiments of Intraocular Lens

Several embodiments of an intraocular lens (IOL) are now described. Withreference now to FIGS. 1D and 2-4, there is shown an embodiment of anintraocular lens (IOL) system 10 for insertion into a capsular bag 12having a zonular region 14, an anterior region 14 a and a posteriorregion 14 b. The IOL system 10 has a shape changing optical element 16including lens body 17, and at least one accommodating element 18connected thereto. The IOL system 10 is adapted to accommodate.

In one embodiment the accommodating element 18 includes a plurality ofspaced apart contacting elements 20 each adapted to separately engage aportion of the zonular region sufficient to substantially maintain thenatural shape of the capsular bag. For example, the contacting elements20 can substantially maintain the capsular bag at various percentagevolumes of the naturally occurring capsular bag, e.g., a capsular bagbefore capsulorhexis.

The outer surface of the capsular abutting portion of the contactingelements is configured to remain separate from but substantiallymaintain the naturally spherical shape of the capsular bag. Theaccommodating element 18 is positioned relative to the optical element16 and configured to cooperate with at least one of the ciliary muscleof the mammalian eye, the zonules of the mammalian eye and/or thevitreous pressure in the eye to effect an accommodating shape and adisaccommodating shape change to the optical element.

Accommodating Element

FIGS. 1D and 2-5 show exemplary embodiments of the accommodating element18. The accommodating element 18 is positioned relative to the opticalelement 16 and configured to cooperate with at least one of the ciliarymuscle of the mammalian eye, the zonules of the mammalian eye and thevitreous pressure in the eye to effect an accommodating shape and adisaccommodating shape change to the optical element 16. Theaccommodating element 18 is connected to both the anterior portion 24and a posterior portion 26 of the capsular bag 12 to transmit the forceor spatial displacement generated at the anterior and posterior portionsof the capsular zonular contact region to the force transmitting element42. By providing such configuration, the naturally occurring compressionof the capsular bag into a more ovoid shape provides additional force orspatial displacement for transmittal to the optical element 16.

The accommodating element 18 may be configured and positioned tomultiply or increase the amount of force or spatial displacementprovided by at least one of the ciliary muscle of the mammalian eye, thezonules of the mammalian eye and/or the vitreous pressure in the eye tothe force translating member 42. The accommodating element 18 canincreases the spatial displacement or force transmitted by variouspercentage values. It should be appreciated that the accommodatingelement 18 can increase the spatial displacement or force transmitted byvalues other than the aforementioned.

With reference still to FIGS. 2-5, the accommodating element 18 includesat least two contacting elements 20 disposed circumferentially betweenthe optical element 16 and the capsular bag 12. Each contacting element20 has a capsule abutting portion 22 that contacts a substantial portionof the interior of the capsular bag 12, a sufficient amount tosubstantially maintain the original sphericity of the capsular bag. Theamount contacted is one factor in enabling the natural mechanisms ofaccommodating and disaccommodating to effect the desired 3D change. Invarious embodiments, the spaced apart capsular contacting portions 22circumferentially or polarly contact the capsular sac at variouspercentage values of the interior capsular bag corresponding to thezonular contact region 14.

The abutting portion 22 may also be in contact with both the posteriorand anterior portions of the zonular contacting regions. In such anembodiment, the spaced apart capsular contacting portions 22 can contactvarious percentage values of the interior capsular bag corresponding tothe anterior and posterior zonular contact regions 14. The contactingelements can have various shapes. In one embodiment, the plurality ofcontacting elements may be in the shape of a plurality of orange slicesections.

With reference to FIG. 2, the portion of the capsular bag removed bycapsulorhexis is the portion of the capsular bag labeled D′-E′ whichcorresponds to that portion of the capsular bag which is the orthogonalprojection of the radius DE along axis X-X of FIG. 2. In an embodiment,DE is about 2 mm from the center or optical axis y-y. The zonularcontact portion AC′ corresponds to that portion of the capsular bagwhich is defined by the equatorial apices (labeled A in FIG. 2) and theorthogonal projection of the radius segment AC along axis XX.

With reference to FIG. 2, the anterior portion of the zonular regioncorresponds to that portion of the capsular bag extending posteriorlyfrom C′ towards the equatorial apice A, which corresponds to thatportion of the capsular bag defined by the orthogonal projection of theposition C′ and the orthogonal projection of a point along the arc C′A,for example B′ and the resulting anterior contacting radius CB. For thepurposes of example, 50% of the anterior zonular contact region would bethat defined by the orthogonal projection of radius CB. For the purposesof example, if the anterior zonular contact point is at about 3.5 mmradially inward from the apices A, then the anterior 50% includes thatportion of the capsular sac that is defined by an orthogonal at about50% from the anterior contact point, or about 1.75 mm from the apices,and the orthogonal from anterior contact point C. The posterior portionof the zonular contact region can be determined in a like way fromapices A, posterior contact point C″ and B″.

With reference still to FIG. 2, an optional equatorial groove 50 can becircumferentially defined in the accommodating element 18 and a capsulartensioning ring 52 disposed therein. In this embodiment, the equatorialgroove is in substantially the same plane as the plane defined by theaxis X-X, orthogonal to the optical axis Y-Y.

With reference now to FIG. 3, there is shown one embodiment of theaccommodating element 18, positioned between the optical element 16 andthe capsular bag 12. In this embodiment, the accommodating element 18includes a first linking element 30 and a second linking element 32.Each of the linking elements 30 and 32 has a respective first end 34 and36 connected to the capsular bag contacting element 20 and a secondrespective end 38 and 40 flexibly connected to each other and connectedto the optic element 16 through a force transmitting element 42. Each ofsaid linking elements is angled obliquely relative the tangent at thefirst end and the capsular bag. The oblique angle can vary.

The oblique angle of the linking elements increases the transmission ofcompressive force or spatial displacement provided at the anterior andposterior portions of the capsular sac. By this configuration andpositioning, the accommodating element 18 cooperates with at least oneof the ciliary muscle of the mammalian eye, the zonules of the mammalianeye and the vitreous pressure in the eye to effect accommodating anddisaccommodating shape change to the optical element 16 assembly alongthe optical axis YY. In one embodiment, as shown in FIG. 3, thecontacting element 20 is an arcuate bag, comprising an outer wall 44abutting the capsular bag 12.

Referring now to FIG. 4, there is shown another embodiment of theaccommodating element 18, positioned between the optical element 16 andthe capsular bag 12. In this embodiment, the arcuate bag 20′ includes afirst inner wall 30′ and second inner wall 32′ that act as the firstlinking element 30 and second linking element 32, respectively, definingan interior chamber 46 for receipt of a resilient fluid material.Exemplary fluid materials include, but are not limited to silicone oil,hydrogels, and saline In this embodiment, the linking elements may alsobe arms or filaments disposed in or on the surface of the first andsecond interior walls. Additional embodiments of the arcuate bag includeat least one or both of the inner walls 30′ or 32′ of a material havinga higher Young's modulus) allowing such walls to distend furtherradially inwards with a given force applied to the contacting element20.

Referring to FIG. 5, the contacting elements 20 may be in the form of aresilient framework including filaments 30″ and 32″ that act as thefirst linking element 30 and second linking element 32, respectively. Insuch embodiment, the capsular abutting portion 22 comprises an arcuatefilament or framework contacting the zonular region and for connectionto the respective linking filaments, e.g, 30″ and/or 32″. It should berecognized that any of the contacting element embodiments depicted inFIGS. 3-5 could be interchangeably used with the respective forcetransmitting element 42 and optical elements 16.

Referring to FIGS. 6 and 7, there is shown schematic views of the firstand second linking arms. In another embodiment, the first and secondlinking arms are of unequal lengths.

Referring to FIGS. 8 and 9, the forces (as depicted by the arrowsgenerally anteriorly and radially inward) result in the force vectors wand v applied to linking arms 30 and 32 which results in the forcevector indicated by arrow u in the posterior and radially outwarddirection. Thus by having first and second linking arms 30 and 32 atoblique angles relative the tangents at the contact points, advantageousaccommodative forces or spatial displacement are provided.

Referring to FIG. 10, in another embodiment of the present invention,the accommodating member includes a plurality of engaging struts eachhaving a first end in contact with the capsular bag and a second endextending obliquely therefrom. Adjacent engaging struts extend obliquelyin opposite directions and are pivotally engaged with one another. Thesecond ends are in contact with the optical element. The accommodatingelement 18 includes a plurality of engaging struts 60 having a first end62 in contact with the capsular bag 12 and extending obliquely therefromand a second end 64 in contact with the optical element 16 to provideradially inward compressive force to the optical element. Adjacentengaging struts 60 are pivotally engaged to enable a scissor likepivoting and thus expansion and contraction. It should be appreciatedthat the engaging struts can be of a sufficient angle to pivotallyengage the respective adjacent strut so that radially inward compressionof the engaging strut by the capsular bag 12 will result in a radiallyinward displacement at the second end 64 of the strut 60 of an amountgreater than the radial displacement experienced by the first end 62engaging the capsular bag 12. Furthermore, such radial displacement iseffected with sufficient force to effect a shape change in the opticalelement 16 from a disaccommodative shape to an accommodative shape.

Referring to FIGS. 3-5, a force transmitting element 42 transmits theforce or spatial displacement generated by the accommodating element 18to the optical element 16. The force transmitting element 42 can be inthe form of an third linking arm, a lever, an circumferential annulus ora frusto-conical annulus, extending radially inward from theaccommodating elements 18 disposed between the contacting element 20 andthe optical element 16. In one embodiment, the force transmittingelements 42 are configured or otherwise structured to convey theincreased force generated by the translating members to the opticalelement 16. In one embodiment, the force transmitting elements aregenerally medially disposed within the capsular bag. One medialdisposition can be equatorially and/or equidistant from the posteriorand anterior capsular sac portions.

FIGS. 11-14 show an exemplary plurality of combined force transmittingelements and contacting elements. The elements are merged into arcuatecombination members 80 disposed between and circumferentially about theoptical element 16 and the capsular bag 12. In one embodiment, theplurality of arcuate members 80 contact the capsular bag 12 aspreviously described with respect to the contacting members 20. In oneembodiment, the arcuate members 80 are formed of a harder material thanthat of the optical element 16, which includes lens body 17. A change inhardness or durometer can be accomplished via a change in material. Forexample, a higher durometer material (such as a silicone) can be usedfor the arcuate members than the material for the optical element. Forexample, the arcuate members can be made from silicone while the opticalelement is made from a softer hydrogel. Hardness can be determined orquantized using the Shore A or Shore D scale.

Referring to FIG. 11-14, contacting elements are configured and sized toreceive a conventional accommodative lens or a frusto-conical IOL. Bythe use of the accommodating element 18 in combination with conventionalaccommodative lens systems, the forces generated by the naturalaccommodative elements and the maintenance of the spherical shape of acapsular bag, there is an increase in the amount of force provided bythe accommodative structure to enable accommodative shape changing ofthe optic element 16 to and from an accommodative shape to adisaccommodative shape.

With reference now to FIG. 15, the arcuate member 80 includes a hollowmember which is constructed to enable multiplication or an increase ofthe concentric displacement with the commensurate increased lens bodyaccommodative shape change. In one such embodiment, the arcuate member80 is trapezoidal in cross-section, e.g., the width of the arcuatemember is wider at the periphery than at the interior. The interiorportion of the arcuate member is formed of a material that is moredistensible than the exterior portion such that a radial compression ofa given amount at the exterior portion of the arcuate member wouldresult in greater distention, distance wise, by the interior portion.

Referring to FIG. 16, in an embodiment, each arcuate member 80 comprisesan arcuate haptic wire frame and a lens body or optical element 16 sizedto fit within a concentric interior space defined within the frame,

It will be recognized that the accommodating element 18 provides aradially outward biasing sufficient to maintain contact with theinterior surface of the capsular bag 12, e.g., with the zonular region14 without requiring fusion of the accommodating element 18 to the bag12. Thus upon release of the zonular compression, the translatingmembers are biased to return to an disaccommodative position radiallyoutward from the accommodative position.

Optical Element

Exemplary embodiments of the optical element 16 are now described.Referring to FIGS. 1D, 2 and 5, the optical element 16 may include alens body 17. FIGS. 18-20 show an enlarged view of an exemplary lensbody 17, which may be comprised of a flexible material that can distendfrom a first position or shape to a second accommodative position orshape. There are a number of ways to cause reshaping and/or axialmovement of the optical element 16.

FIG. 17 illustrates an outer lens portion 90 structured to include acenter section 92 of reduced thickness. The center section 92 surroundsthe optical axis 94 of the lens body 17 and is located on or near theanterior face 96 thereof. When the IOL 10, and in particular lens body17, is compressed, for example by squeezing peripheral regions 98 and100 together, the lens body is reshaped by an outward bowing of theanterior face 96. This squeezing is generally similar to the compressiveforce applied to the lens body 17 by the eye in which the IOL 10 isplaced. The outward bowing or reshaping is especially pronounced atregion 102, because the reduced thickness center section 92 isrelatively more prone to give way from the internal pressure of a corelens portion 91. The core lens portion 91 thus extends forward, as seenfor example in the central region 102 in FIG. 18.

The extended central region 102 of lens body 17 provides near visioncorrection power. The remainder of the outer portion 90, having athickness greater than center section 92, is more resistant to reshapingunder such compression than is center section 92. Therefore, under suchcompression, the annular region 104 of lens body 17 extending radiallyoutward of center section 102 continues to provide distance visioncorrection power. Thus, the regions 102 and 104 of lens body 17, undercompression, provide both near and distance vision correction powers,respectively. In other words, the anterior surface 96 of lens body 17 isa multifocal surface with the optic under compression. In contrast, withthe lens body 17 in the rest position as in FIG. 17, the anteriorsurface 96 is a monofocal surface.

FIG. 18 illustrates an alternative embodiment of the IOL of the presentinvention which is substantially the same as that shown in FIG. 17,except for a different construction of the outer portion 90. The centersection 92 is made of a material that is relatively more susceptible tooutward bowing than is the peripheral region surrounding it. The centersection 92 may be injection molded in combination with the peripheralregions surrounding it to provide a relatively seamless anduninterrupted anterior face 96, at least in the rest position of theIOL. When the peripheral regions 98 and 100 are squeezed together thecore lens portion 91 is placed in compression thus forcing the centersection 92 in the anterior direction as shown in the extended region102. The material of the outer portion 90 can be generally consistent,though the center section 92 has a different stiffness or elasticitythat causes it to bow outward farther than the surrounding region.

The extent to which central region 102 extends forwardly, and thereforethe magnitude of the near vision correction power obtainable by IOL 10,depends on a number of factors, such as the thickness of center section92, the overall structure of the outer portion 90 and/or the innerportion 91, the material of construction of the outer portion and/or theinner portion, the amount of force that the eye in which IOL 10 isplaced can exert on the IOL and the like factors. The amount or degreeof near power correction obtainable from IOL 10 can be controlled, or atleast partially controlled, by varying one or more of these factors.

FIG. 19 illustrates an alternate IOL, shown generally at 10. Except asexpressly described herein, alternate IOL 10 of FIG. 19 functionssimilarly to IOL 10 of FIGS. 18 and 19. One difference between IOL 10 ofFIG. 17 and FIG. 19 relates to the structure of outer portion 92 of lensbody 17. Whereas outer portion 90 has only a single center section 92 ofreduced thickness, outer portion 92 of FIG. 19 has several three regions111, 113 and 115 of reduced thickness. The central region 111 surroundsthe optical axis 94 and has a variable thickness. Region 113 is anannular region located outwardly of region 111 and annular region 115 islocated outwardly of region 111 and is reduced in radial dimensionrelative to region 111.

Under compressive force from the eye in which IOL 10 is placed, theinner portion 91 forces the regions 111, 113 and 115 to extendoutwardly. The variable thickness of region 111 leads to a centralregion of the compressed lens body 17 having an intermediate (betweennear and far) vision correction power. The reduced thicknesses of outerregions 113 and 115 lead to two regions of the compressed lens body 17having near vision correction powers. In general, the multifocalanterior surface of compressed lens body 17 has more varied opticalpowers than does the multifocal anterior surface of compressed lens body17. The optical power curve of compressed lens body 17 may resemble, atleast in general, a power curve as disclosed in the above-noted PortneyU.S. patent which is incorporated herein by reference. Such a variedmultifocal configuration provides the wearer of IOL 10 with enhancedvision over a wider range of distances.

Referring to FIGS. 20-25, in another embodiment, lens body 300 has ananterior surface 302, a posterior surface 304 and a peripheral edge 306,which includes a plurality of concentric annular sections 310, 312, and314, each of the concentric sections possessing different rigidity orsoftness characteristics to cause them to bend or bow in the anteriordirection at different rates when under radial compressive stresses. Forexample, the intermediate section 312 may be relatively harder thaneither the center section 310 or outer peripheral section 314, and thusbe less susceptible to forward bowing. This configuration is seen inFIGS. 22 and 23 where the center section 310 and the outer peripheralsection 314 exhibit more pronounced curvatures than the intermediatesection 312. In this way, the center section 310 provides near vision,while the intermediate section 312 and outer peripheral section 314provide varying degrees of far vision correction. The three sections310, 312, and 314 may be injection molded to provide a relativelyseamless and uninterrupted anterior face 302, at least in the restposition of the IOL 300.

Referring again to FIG. 2, in another embodiment, the optical element 16includes a flexible or distendable bag 120 attached to forcetransmission member 42. Lens body 17 is incorporated into anterior wall122. The application of radially inward compressive force or spatialdisplacement to the anterior wall through force transmission member 42affects an alteration of the lens body 17 shape and thus resulting focallength, providing an accommodative effect.

Referring to again to FIG. 5, in another embodiment the optical elementincludes an interior wall 70, posterior wall 72 and an anterior wall 74that collectively define an interior central chamber 76. The anteriorwall can be comprised of material having a lower Young's modulus thaninterior wall and the posterior wall. The interior chamber is configuredto cooperate with the translating member to effect an accommodating anddisaccommodating shape change in the lens body 17. In this embodiment,the force transmitting element 42 includes a first end 77 and a secondend 78, the first end in contact with the accommodating element 18 and asecond end being t-shaped to increase the contact area with the interiorwall 70, thereby distributing the radially inward force over a broaderarea.

Exemplary Materials

The accommodative IOL of the present invention, in one embodiment, ismade from a shape-memory material. Shape memory materials arestimuli-responsive materials. They have the capability of changing theirshape into a temporary shape under an external stimulus. The stimuluscan be, for example, a temperature change or the exerting of an externalcompression (or stretching) force. Once the external stimulus iseliminated, the shape memory material will change back into its initialshape. A recent review paper of “Shape-Memory Polymers” was published inAngewandete Chemie, International Edition 41(12) 1973-2208 (2002), andis herein incorporated by reference.

The disclosed accommodative IOL is formed of a shape memory materialwith appropriate softness. All the IOLs currently on the marketplacehave a durometer hardness of at least 25 Shore A. Hardness can bedetermined using a Durometer hardness tester using the A scale(ASTMD-2240; DIN 53 505; ISO7619 Part 1; JIS K 6301; ASKER C-SRIS-0101).For example, one lens is Alcon's ACRYSOF® family IOLs with the durometerof 45 Shore A. Similarly, soft silicone IOLs have a durometer of 38-40Shore A (Christ et al, U.S. Pat. No. 5,236,970) and a relatively lowdurometer hardness for silicone IOL material was disclosed to be 28-30Shore A in U.S. Pat. No. 5,444,106 by Zhou et al. In a non-limiting,exemplary embodiment, a material suitable for the lens disclosed hereinhas a hardness in durometer Shore A at least about 5 times softer thanthose used in the regular IOL applications. Thus, the durometer hardnessfor the accommodative IOL is no greater than about 5 Shore A, an isabout 1 Shore A or less in one embodiment. Where feasible, material of alower Shore A hardness such as 15 A may be used for the optic(s), andmaterial of higher hardness such as 35 A may be used for the balance ofthe lens system 100. The optic(s) may be formed from a photosensitivesilicone to facilitate post-implantation power adjustment as taught inU.S. patent application Ser. No. 09/416,044, filed Oct. 8, 1999, titledLENSES CAPABLE OF POST-FABRICATION POWER MODIFICATION, the entirecontents of which are hereby incorporated by reference herein.

Suitable materials for the preparation of the accommodative IOLsdisclosed herein include, but are not limited to, acrylic polymers,silicone elastomers, hydrogels, composite materials, and combinationsthereof. Some materials for forming the lens system 100 includesilicone, acrylics, polymethylmethacrylate (PMMA), block copolymers ofstyrene-ethylene-butylene-styrene (C-FLEX) or other styrene-basecopolymers, polyvinyl alcohol (PVA), polyurethanes, hydrogels or anyother suitable polymers or monomers. Methyl-methylacrylate monomers mayalso be blended with any of the non-metallic materials discussed above,to increase the lubricity of the resulting lens system (making the lenssystem easier to fold or roll for insertion, as discussed furtherbelow). The addition of methyl-methylacrylate monomers also increasesthe strength and transparency of the lens system. One particularlyuseful acrylic polymeric material for use as a material of constructionof the members 72 is a polymeric composition produced from the followingmixture of monomers: Ethyl acrylate 57.1% by weight Ethyl methacrylate27.7% by weight Trifluoroethyl methacrylate 9.82% by weight Ethyleneglycol dimethacrylate 3.75% by weight UV chromophore 1.5% by weightInitiator (thermal) 0.13% by weight Suitable materials for theproduction of the subject IOL system 32 include but are not limited tofoldable or compressible materials, such as silicone polymers,hydrocarbon and fluorocarbon polymers, hydrogels, soft acrylic polymers,polyesters, polyamides, polyurethane, silicone polymers with hydrophilicmonomer units, fluorine-containing polysiloxane elastomers andcombinations thereof. An exemplary material for the production of IOLsystem disclosed herein is a hydrogel made from 2-hydroxyethylmethacrylate (HEMA) and 6-hydroxyhexyl methacrylate (HOHEXMA), i.e.,poly(HEMA-co-HOHEXMA). Poly(HEMA-co-HOHEXMA) is a material for themanufacture of IOL due to its equilibrium water content of approximately18 percent by weight, and high refractive index of approximately 1.474,which is greater than that of the aqueous humor of the eye, i.e., 1.336.

A high refractive index is a desirable feature in the production of IOLsto impart high optical power with a minimum of optic thickness. By usinga material with a high refractive index, visual acuity deficiencies maybe corrected using a thinner IOL. Poly(HEMA-co-HOHEXMA) is a desirablematerial in the production of IOL system 10 due to its mechanicalstrength, which is suitable to withstand considerable physicalmanipulation. Poly(HEMA-co-HOHEXMA) also has desirable memory propertiessuitable for IOL use.

IOLs manufactured from a material possessing good memory properties suchas those of poly(HEMA-co-HOHEXMA) unfold in a more controlled manner inan eye, rather than explosively, to its predetermined shape. The uniquedesign of the subject IOL system 10 with accommodative elements 18and/or force translating elements 44 manufactured from a material havinggood memory properties also provides improved control of such elementsunfolding upon insertion thereof in eye 8. Explosive unfolding of IOLsis undesirable due to potential damage to delicate tissues within theeye. Poly(HEMA-co-HOHEXMA) also has dimensional stability in the eye,which is desirable. The IOL 10 can be produced by molding the outer lensportion, and transfer members separately. Molding can be employed toform the combination of the inner lens portion, the transfer members andthe outer lens portion.

Furthermore, in an embodiment the optical element has a sufficient opticresolution and a predetermined optic diopter power tailored for aspecific patient's refractive error. The accommodative IOL has itsinitial first configuration with its first diopter (D1). In anembodiment, the accommodative IOL in its first configuration engageswith the capsule once it is implanted inside the capsule after the agednatural lens is removed. Because the IOL or at least its optic portionis made from a shape-memory material with an appropriate softness, theinteraction of the IOL with the capsule will force it to change into asecond configuration having a second diopter (D2). The degree in thelens shape change as well as the diopter change is dependent on itssoftness and its engagement force with the capsule.

The optical element 16 and/or the lens body 17 of the IOL system 10 canalso be formed from layers of differing materials. The layers may bearranged in a simple sandwich fashion, or concentrically. In addition,the layers may include a series of polymer layers, a mix of polymer andmetallic layers, or a mix of polymer and monomer layers. In particular,a Nitinol ribbon core with a surrounding silicone jacket may be used forany portion of the lens system 10 except for the optics; anacrylic-over-silicone laminate may be employed for the optics. A layeredconstruction may be obtained by pressing/bonding two or more layerstogether, or deposition or coating processes may be employed.

Where desired, various coatings are suitable for components of the IOL10. A heparin coating may be applied to appropriate locations on the IOL10 to prevent inflammatory cell attachment (ICA) and/or posteriorcapsule opacification (PCO); possible locations for such a coatinginclude the accommodating element 18, and the posterior face of theoptical element 16 or the lens body 17. Coatings can also be applied tothe IOL 10 to improve biocompatibility; such coatings include “active”coatings like P-15 peptides or RGD peptides, and “passive” coatings suchas heparin and other mucopolysaccharides, collagen, fibronectin andlaminin. Other coatings, including hirudin, teflon, teflon-likecoatings, PVDF, fluorinated polymers, and other coatings which are inertrelative to the capsular bag may be employed to increase lubricity atlocations (such as the optics and distending members) on the lens systemwhich contact the bag, or Hema or silicone can be used to imparthydrophilic or hydrophobic properties to the IOL 10.

In an embodiment, the IOL 10 and/or the mold surfaces is subjected to asurface passivation process to improve biocompatibility. This may bedone via conventional techniques such as chemical etching or plasmatreatment.

The accommodating element 18 and/or the force transmitting element 42may be manufactured by preparing a solution made of polyetherurethaneurea in dimethylacetamide. Very thin sheets or curved sections of thepolyetherurethane urea material may be made by dip-casting. Dip-castingis achieved by dipping a mandrel into the polyetherurethaneurea/dimethylacetamide solution. The thickness of flexible accommodatingelements 18 and/or the force transmitting element 42 is controlled bythe number of dips of the mandrel into the solution. Such dip-castingmay be suitable for forming curved accommodating elements 18 and/or theforce transmitting element 42 depending on the design desired. Whereapplicable, individual flexible accommodating elements or componentsthereof are cut off the mandrel for attachment to optical element 16. Aflat sheet of polyetherurethane urea material may be made by pouring thepolyetherurethane urea/dimethylacetamide solution onto a flat plate orby using a film casting knife on a flat plate. Individual accommodatingelements 18 or applicable portions of the optical element 16 may then becut or stamped from the sheet.

Once formed, the subject accommodating elements 18 may be permanentlyattached to optical element 16 by numerous methods including but notlimited to fastening within a pre-formed optic slot using glue, staking,plasma treatment, friction, or like means or combinations thereof. Thepolyurethane elastomer material useful for the manufacture of thesubject accommodating elements 18 can be a polyether urethane materialand/or a polyether urethane urea material such as but not limited to a2000 molecular weight polytetramethylene glycol, methylene diphenylenediisocyanate and methylene diamine material.

One particularly useful acrylic polymeric material for use as a materialof construction of the accommodating members is a polymeric compositionproduced from the following mixture of monomers: Ethyl acrylate 57.1% byweight Ethyl methacrylate 27.7% by weight Trifluoroethyl methacrylate9.8% by weight Ethylene glycol dimethacrylate 3.8% by weight UVchromophore 1.5% by weight Initiator (thermal) 0.1% by weight.

Furthermore, appropriate surfaces (such as the outer edges/surfaces ofthe contacting elements, accommodating elements, etc.) of the IOL 10 canbe textured or roughened to improve adhesion to the capsular bag 12.This may be accomplished by using conventional procedures such as plasmatreatment, etching, dipping, vapor deposition, mold surfacemodification, etc. As a further means of preventing ICA/PCO, aposteriorly-extending perimeter wall (not shown) may be added to thelens body 17 so as to surround the posterior face of the posterioroptic.

A relatively thick cross-section of the optical body 17 ensures that itwill firmly abut the posterior capsule with no localized flexing. Thus,with its relatively sharp rim, the posterior face of the optical element16 or lens body 17 can itself serve as a barrier to cellular ingrowthand ICA/PCO. In order to achieve this effect, the optical element 16and/or the lens body 17 can be made thicker than conventionalintraocular lenses. As an alternative or supplement to a thick posteriorviewing element, cell growth may be inhibited by forming a pronounced,posteriorly-extending perimeter rim on the posterior face of the opticalelement 16 and/or the lens body 17. Upon implantation of the IOL 10, therim firmly abuts the inner surface of the capsular bag 12 and acts as aphysical barrier to cell growth between the posterior face of theoptical element 16 and/or the lens body 17 and the capsular bag 12.

In an embodiment, the selected material and lens configuration is ableto withstand secondary operations after molding/casting such aspolishing, cleaning and sterilization processes involving the use of anautoclave, or ethylene oxide or radiation. After the mold is opened, thelens undergoes deflashing, polishing and cleaning operations, whichtypically involve a chemical or mechanical process, or a combinationthereof. Some suitable mechanical processes include tumbling, shakingand vibration; a tumbling process may involve the use of a barrel withvarying grades of glass beads, fluids such as alcohol or water andpolishing compounds such as aluminum oxides. Process rates are materialdependent; for example, a tumbling process for silicone can utilize a 6″diameter barrel moving at 30-100 RPM. It is contemplated that severaldifferent steps of polishing and cleaning may be employed before thefinal surface quality is achieved.

A curing process may also be desirable in manufacturing the IOL 10. Ifthe lens system is produced from silicone entirely at room temperature,the curing time can be as long as several days. If the mold ismaintained at about 50 degrees C., the curing time is reduced to about24 hours; if the mold is preheated to 100-200 degrees C. the curing timecan be as short as about 3-15 minutes. Of course, the time-temperaturecombinations vary for other materials.

Exemplary Method of Implantation

There are now described exemplary methods of implanting the IOL into theeye. In accordance with one embodiment, there is a method for implantingthe accommodative IOL into the capsule after the aged crystalline lensis removed. The method comprises (a) providing an accommodative IOL,including a shape changing optical element, in its first configurationhaving a corresponding first optic diopter (D1) and resolutionpredetermined for a patient's specific refractive error; (b) removing anaged human crystalline lens surgically; and (c) implanting theaccommodative IOL into the patient's capsule. The IOL is configured tocontact a sufficient amount of the capsular bag to substantiallymaintain the sphericity of the capsular bag, transmit forces fromanterior and posterior portions of the capsular bag to a forcetransmitting element (such as an equatorially disposed forcetransmitting element) and effect shape changes in the lens body from itsfirst shape configuration to a second shape configuration due to atleast one of the ciliary muscle of the mammalian eye, the zonules of themammalian eye and the vitreous pressure in the eye.

This results in a change in the IOL's optic power from its first diopter(D1) to a second diopter (D2). In a non-limiting, exemplary embodiment,the difference between D1 and D2 is generally in the range of about 1-5diopters, in the range about 2-4 diopters, or about 3 diopters. Inanother embodiment, IOL 10 is such that the amount of accommodationachievable is in the range of about 1 to about 4 or about 5 or about 6diopters.

The method for the implantation of the present accommodative IOLprovides additional force or spatial displacement to the optical elementand effect an accommodating shape change to the lens body 17. When theeye is in the accommodative state, at least one of the of the ciliarymuscle of the mammalian eye, the zonules of the mammalian eye and thevitreous pressure in the eye forces the IOL into its secondconfiguration with a second diopter suitable for the near vision. Oncethe eye becomes unaccommodative, an outward biasing of the contactingelements and the zonules stretch the capsule to an increased diameter,the accommodative IOL inside the capsule also increases its diameter andeffects a return to the disaccommodative state.

This is advantageous over those IOL's that are generally planar enablingthe capsular bag to collapse and reduce its ability to utilize thenatural accommodative mechanisms of the ciliary muscles, zonules andvitreous matrix pressure changes. Furthermore, by using a more effectiveaccommodating elements and force transmitting elements, sufficient forceor spatial displacement is provided to effect a change in the shape oflens body. Since the amount of force required to effect a shape changein the lens is less than that of moving the lens the amount necessary toachieve the desired D change, the disclosed IOL provides accommodativeeffects. This accommodation to unaccommodation can be switched back andforth repeatedly, just as in a young accommodative natural eye. It iswell known that presbyopia patients still have active zonular stretchingmovement. It is the natural crystalline lens, which becomes too rigid tochange its shape when zonules stretch or relax, that causes thepresbyopic condition. The disclosed IOLs overcome that problem.

Without limiting this disclosure to any particular theory or mode ofoperation, the eye is believed to act on optical element 12 as follows.With the capsular bag's sphericity aided by the contact by a substantialportion of the zonular region, the zonules ZS and the ciliary muscle CMof the eye are effective to move the capsular bag 12, and an increasedforce generated by including that generated by the anterior andposterior capsular bag portions are transmitted through, in oneembodiment, a generally equatorially disposed force transmitting memberto the shape changing optical element. This provides accommodationwithout moving a plurality of lens relative to one another or axiallymoving the lens body along the optical axis.

Thus, with the ciliary muscle being fully relaxed, the lens body 17 isin a relatively flat disaccommodative configuration. Such configurationof lens body 17 provides effective monofocal distance vision to the eye.This configuration is at least generally illustrated in FIGS. 7 and 22.With IOL 10 in the position as shown in FIGS. 8 and/or 23, far away ordistant objects are brought into focus. In this position, IOL functionsmuch like a conventional monofocal IOL.

If a near object is to be viewed, the ciliary muscle CM contracts orconstricts causing the zonules ZS to relax tension on the capsular bag12 and the IOL 10 included therein. IOL 10 is reshaped into a secondconfiguration, illustrated generally in FIG. 18. This action of theciliary muscle CM and zonules ZS causes a reshaping of the opticalelement 16 and/or the lens body 17 so that central anterior region 102becomes apparent. This region 102 surrounds the optical axis 94 andprovides near vision correction. The annular region 104 radiallyoutwardly of region 102 continues to be configured for distance visioncorrection. In effect, the configuration of optical element 16 and/orlens body 17 illustrated in FIG. 18 is a multifocal configuration sinceboth near vision correction and distance vision correction are present.When the ciliary muscle CM again relaxes, the IOL 10 returns to thefirst configuration or disaccommodative shape, shown generally in FIG.17.

Thus, the present IOL 10 has the ability, in cooperation with the eye,to be reshaped to provide for both distance focus and near focus, and tobe returned to its first configuration in which only distance focus isprovided. In an embodiment, IOL 10, and in particular lens body 17, issuch that the amount of accommodation achievable at region 92 is in therange of about 1 to about 4 or about 5 or about 6 diopters.

Accommodative Action

A method of enabling lens accommodation, is provided including the stepsof providing an accommodating element configured for contacting at least50% of the zonular region. The accommodating element positioned relativeto an optical element and configured to cooperate with at least one ofthe ciliary muscle of the mammalian eye, the zonules of the mammalianeye and the vitreous pressure in the eye to effect an accommodatingshape and a disaccommodating shape change to the optical element. Ashape changing lens body is coupled to the accommodating element,wherein radial inward forces at the anterior and posterior capsular bagare transmitted through a generally medially disposed force transmittingelement to cause a shape change to a surface curvature of the lens body,and wherein radial outward forces cause the accommodating element tocause a second shape change to said lens curvature.

The disclosed accommodating IOLs cooperate with the eye to achieveadvantageous amounts, including enhanced amounts, of accommodation. Suchaccommodation, as described herein, is often increased, for examplerelative to previous monofocal accommodating IOLs. In addition,halo/glare phenomena are reduced, for example, relative to previousmultifocal IOLs.

While there is shown and described herein certain specific embodimentsof the present invention, it will be manifest to those skilled in theart that various modifications may be made without departing from thespirit and scope of the underlying inventive concept and that the sameis not limited to the particular forms herein shown and described exceptinsofar as indicated by the scope of the appended claims.

The following examples are intended to be illustrative of, but notlimiting of, the present invention.

Example 1 The Preparation of a Synthetic Human Capsule

A synthetic human capsule can be made from NuSil MED 6820 silicone. Thecapsule could have an inner equatorial diameter of 9.3 mm, verticalcentral thickness of 3.8 mm with posterior radius of 7 mm and anteriorsurface of 10 mm. Both posterior wall thickness and anterior wallthickness can be about 0.1 mm, mimicking the natural human capsule. Thecapsule also could have a 3.8 mm capsulorhexis in the central area ofthe anterior surface. In addition, the capsule may have a thin (about0.1 mm) flange around the equator that can be clamped in a retainingring to fix the capsule in position. The capsule could be transparent,with 99% visible light transmission.

Example 2 The Preparation of Accommodative IOLs of Various Dimensions

Into a fused silica mold could be added a pre-gel prepared from themixture of stearyl methacrylate (54% by weight), lauryl acrylate (45% byweight), and 1% of UV absorber,2-(2′-hydroxy-5′acryloxypropylenephenyl)-2H-benzotriazole, as well as0.075% of crosslinker, ethylene glycol dimethacrylate. The mold couldthen be placed in a pre-heated oven at 110.degree. C. for 16 hours.After the mold is taken out from the oven and cools down to roomtemperature, the mold could be placed in a refrigerator for about 2hours. The mold could then opened, and a white or translucent solid IOLcould be carefully removed from the mold. In this way, two differentdimensions of accommodative IOLs are prepared. The first group couldhave a diameter of 9.0 mm, central lens thickness of 3.0 mm, and edgethickness of 1.0 mm with an optical diopter power of 27 D, while thesecond group could have a diameter of 9.9 mm, central lens thickness of2.3 and edge thickness of 1.0 mm with an optical diopter power of 15 D.The durometer hardness of the lenses from both groups could be 4 ShoreA.

Example 3 Accommodation Simulation of the First Group Lens

The first group lens could have an initial diopter power of 27 D(resolution efficiency of 45.1%) measured with a Meclab Optical Benchusing 550 nm wavelength light, 150 mm collimator, 3 mm aperture and 1951US Air Force Target. The IOL could have a central lens thickness of 3.0mm, lens diameter of 9.0 mm, and edge thickness of 1.0 mm, as measuredwith a Nikon V12 optical comparator. The same measurement method is usedfor Example 4. After this lens is implanted into the simulated humancapsule described in Example 1, the resolution and diopter power couldbe measured again. It is anticipated that the lens in the capsule willhave changed its diopter power. The new diopter power in the capsulewould be 30 D, a shift of 3 D from its initial diopter. The resolutionefficiency of the lens inside the capsule could be 40.3%. The diopterincrease in this case could be due to the fact that the lens edgethickness (1.0 mm) is larger than its corresponding dimension of thecapsule (about 0.2 mm). This oversized edge thickness forces the softIOL to move some of its volume toward the central lens area where it hasthe least resistance due to the presence of the capsulorhexis.Consequently, the central lens thickness has been increased and so hasthe lens diopter power.

Example 4 Accommodation Simulation of the Second Group Lens

The second group lens could have diopter power of 15 D (resolutionefficiency of 51%) with a central lens thickness of 2.3 mm, lensdiameter of 9.9 mm, and edge thickness of 1.0 mm. After this lens isimplanted into the simulated human capsule described in Example 1, theresolution and diopter power will be measured again. It is found thatthe diopter power of the IOL inside the capsule could be 20 D with aresolution efficiency of 40%. The big diopter shift (5 D) in this casecould be due to the fact that both the lens diameter (9.9 mm) and thelens edge thickness (1.0 mm) are oversized in comparison with thecorresponding dimensions of the capsule (9.3 mm and about 0.2 mmrespectively). The restriction force by the capsule causes the IOL tochange from its first configuration into its second configuration whichhas a central lens thickness of about 3.0 mm and equatorial diameter of9.5 mm.

Although embodiments of various methods and devices are described hereinin detail with reference to certain versions, it should be appreciatedthat other versions, embodiments, methods of use, and combinationsthereof are also possible. Therefore the spirit and scope of theappended claims should not be limited to the description of theembodiments contained herein.

What is claimed is:
 1. An intraocular lens (IOL) for insertion into acapsular bag having a zonular contact region, the IOL comprising: ashape changing optical element comprising an anterior surface configuredto outwardly bow upon application of a compressive force appliedradially inward at an oblique angle to the optical element creating anaccommodated shape; and an accommodating element coupled to the shapechanging optical element, the accommodating element comprising: (i) atleast one force transmitting element; and (ii) a plurality of spacedapart contacting elements each adapted to contact a portion of thezonular contact region; and (iii) a first linking arm comprising: afirst end obliquely connected to a first region of a first contactingelement of the plurality of spaced apart contacting elements where thefirst contacting element contacts an anterior portion of the capsularbag; and a second end, and (iv) a second linking arm comprising: a firstend obliquely connected to a second region of the first contactingelement where the first contacting element contacts a posterior portionof the capsular bag; and a second end, wherein the second end of thefirst linking arm and the second end of the second linking arm areflexibly connected to each other at a point where each respective secondend also connects to the force transmitting element, wherein theaccommodating element is configured to cooperate with at least one ofthe ciliary muscle of the mammalian eye, the zonules of the mammalianeye and the vitreous pressure in the eye to transmit the compressiveforce to the optical element.
 2. The IOL of claim 1, wherein theplurality of spaced apart contacting elements are each adapted toseparately engage at least 75% of the zonular contact region.
 3. The IOLof claim 1, wherein the plurality of spaced apart contacting elementsare each adapted to separately engage at least 90% of the zonularcontact region.
 4. The IOL of claim 1, wherein the accommodating elementis configured and positioned relative to the optical element and theposterior and anterior portions of the capsular bag to increase thecompressive force transmitted to the optical element.
 5. The IOL ofclaim 1, wherein the first and second linking arms are of unequallengths.
 6. The IOL of claim 1, wherein each of the plurality of spacedapart contacting elements is orange slice shaped.
 7. The IOL of claim 6,wherein each of the plurality of spaced apart contacting elements is aresilient bag.
 8. The IOL of claim 6, wherein each of the plurality ofspaced apart contacting elements is a resilient filament framework. 9.The IOL of claim 1, wherein an equatorial groove is circumferentiallydefined in each of the plurality of spaced apart contacting elements andwherein the accommodating element further comprises a capsulartensioning ring disposed within the equatorial groove.
 10. The IOL ofclaim 1, wherein each of the plurality of spaced apart contactingelements further comprises an interior wall, posterior wall and ananterior wall to define an interior central chamber, the anterior wallcomprised of material having a lower Young's modulus than interior walland the posterior wall, wherein the interior chamber is configured tocooperate with the force transmitting element to effect accommodatingand disaccommodating movement of the anterior wall.
 11. The IOL of claim1, wherein the accommodating element has an elastic modulus greater thanthe elastic modulus of the optical element.
 12. An intraocular lens(IOL) for insertion into a capsular bag, the IOL comprising: a shapechanging optical element comprising: (i) an inner lens portion; (ii) anouter lens body encompassing the inner lens portion and having ananterior center section of reduced thickness surrounding the opticalaxis of an eye; and (iii) a first equatorial region and a secondequatorial region; and an accommodating element disposed between andcircumferentially about the optical element, the accommodating elementcomprising: (i) a first arcuate contacting element adapted to contact afirst zonular contact region of the capsular bag; (ii) a first forcetransmitting element coupled to the first arcuate contacting element ata first end and coupled to the first equatorial region of the shapechanging optical element at a second end; (iii) a second arcuatecontacting element adapted to contact a second zonular contact region ofthe capsular bag; (iv) a second force transmitting element coupled tothe second arcuate contacting element at a first end and coupled to thesecond equatorial region of the shape changing optical element at asecond end; wherein the accommodating element is configured to maintainthe capsular bag in a spherical shape and to transmit a compressiveforce applied radially inward at an oblique angle to the optical elementin cooperation with at least one of the ciliary muscle of the mammalianeye, the zonules of the mammalian eye, and the vitreous pressure in theeye, and wherein the compressive force is transmitted from the first andsecond arcuate contacting elements through the first and second forcetransmitting elements to squeeze the first equatorial region and thesecond equatorial region together causing the center section tooutwardly bow creating an accommodated shape change.
 13. The IOL ofclaim 12, wherein the first and second arcuate contacting elements areeach adapted to separately engage at least 75% of the first and secondzonular contact regions.
 14. The IOL of claim 12, wherein the first andsecond arcuate contacting elements are each adapted to separately engageat least 90% of the first and second zonular contact regions.
 15. TheIOL of claim 12, wherein the first and second force transmittingelements are medially disposed force transmitting elements connectingthe accommodating element to the optical element, the force transmittingelements configured and positioned relative to the accommodating elementand the optical element to transmit radially the compressive force at aposterior portion and an anterior portion of the capsular bag to theoptical element.
 16. The IOL of claim 15, wherein the accommodatingelement is configured and positioned relative to the optical element andthe posterior and anterior portions of the capsular bag to increase thecompressive force provided to the optical element.
 17. The IOL of claim12, wherein each of the first and second contacting elements is orangeslice shaped.
 18. The IOL of claim 17, wherein each of the first andsecond contacting elements is selected from the group of a resilient bagand a resilient filament framework.
 19. The IOL of claim 12, wherein anequatorial groove is circumferentially defined in each of the contactingelements and wherein the accommodating element further comprises acapsular tensioning ring disposed within the equatorial groove.
 20. TheIOL of claim 12, wherein the accommodating element further comprises aninterior wall, posterior wall and an anterior wall to define an interiorcentral chamber, the anterior wall comprised of material having a lowerYoung's modulus than the interior wall and the posterior wall, whereinthe interior chamber is configured to cooperate with the contactingelements to effect the compressive force.